Improvement in devices for firing cannon



3 Sheets--Sheet 1. D. TREADWELL.' l

l Gun-Lock.

D. TREADWELL.V

Gnu-Lock'.

No. 37.017. PatentedNov. 26, 1862 Inventor.

D.' TREADWELL.

. Gun-Look.

3 sheeehsheet 3.

Patented Nov.. 25. 1862.

UNTTED STATES PATENT @Einenn DANIEL TREAD'WELL, OF CAMBRIDGE, MASSACHUSETTS.

IMPROVEMENT lN DEVICES FOR FIRING CANNON.

Spccilicalion forming part of Letters Patent No. 37,0l7-, dated November Q5, 1562.

1o dit` zii/"1,0111, it may concern:

Be it known that I, DANIEL lnnanwnnn of Cambridge, in the county of Middlesex and State of Massachusetts, have iuventedanew and useful Improvement in the Method of Firing Guns or Ordnance; and I do hereby decla-re that the following is a full, clear, and exact description of the construction and operation of the same, taken iu connection with the accompanying drawings, making apart ol this speciication, in which- Figure 1 is a sectional elevation of a portion of the breech of a gun with the mechanism for closing the vent and iguiting the primer attached thereto. Fig. 2 is a plan ofthe same. Fig. 3 is an end elevation of the same. Fi 4 is an end elevation of the opposite end, and Fig. 5 is a separate View ot' the primer in section.

The subiectanatter of my invention relates to the construction and mode oi' operation of the apparatus for discharging guns or ordnance, and is designed to obviate certain difficulties attending the modes oi construction now'usnally employed, which will be briefly stated in order to afford a better understanding of the conditions to which my improvements more particularly apply.

In the guns now used, when the explosion of the charge takes place, the vent being open permits a portion of the gas produced from the charge to escape through it during` the whole time that the projectile is within the gun; This gives rise to certain difficulties, which I will mention. The gases within the gunthus escaping through the vent at the moment of explosion under an enormous pressure, and perhaps also by their chemical agency, produce an erosion of the surface of the metal within the vent, and rapidly wear and enlarge it, so as to require it to be replaced, after a few hundred discharges by au operation well known as bouching The vent when new has to be suiliciently large to insure its being kept free from clogging, and from its further rapid enlargement, the proportion of the charge that escapes through it becomes very considerable in guns firing the ordinary round shot with windage, and the evil isgreatly aggravated both as to the amount of waste of charge and wear of vent bythe greater pressure of the gases in the gun -where an elongated projectile is fired in Fig. l, which will be hereinafter ino without windage, as is the case with modern rifled guns. The escape of this amount of gas 'from the vent, iu addition to the wear and waste produced, is also very prejudicial when the gun is fired with the breech iu some confined space-such as the casemate ol'a fort or between decks of a shi p of ii'ar-where the fire is dangerous, and the smoke becomes a serious inconvenience to the gunuers. These difficulties I obviate by the employment upon the exterior of the gun of certain devices which inclose the vent and primer, with sufficient strength to reta-in the gases of the discharge, and which can be readily removed and replaced to permit all the operations of loading and priming, or -to enable the veut to be used in the usual manner in case of accident-to the vent-stopper or the absence of proper primer.

rlhese devices consist, substantially, in forming upon the exterior of the vent a recess or receptacle for containing a i'ulniuating primer, and employing` therewith a set or'plug, which I call a veutstoppen which closes it, and is confined thereto .by some eliicient means, as will be hereinafter described, and a fulminating primer provided with a casing ot' thin copper or other suitable material, that by its expansion against the sides ot' the recess or vent closes the joint to the escape of the gas,

the primer being ignited by a blow applied to the exterior of the setbyaloclr or otherwise.

In the drawings the letters represent the the saine parts in all the figures.

A represents a portion of the breech of the gun containing the touch-hole, or Vent, as it is called, and to which the apparatus for closing the vent and igniting the primer is attached.

Bis a steel plug screwed into the gun, as shown, forming a vent-pieee, through which the veut a c is bored, which also extends through the walls of the gun to the caliber, as isshown. The upper or outer partei' thevent is enlarged to form a recess or chamber, b, into which the primingcap J is placed, as is seen re partien-lar] y described.

Gis astrong lever, which I call a set-stock, which is jointed atene end to the stud D, which is screwed into the gun, as shown, or othei` wise 'connected with it, --whicli permits the other end of the set-stock to be turned back from the vent out of the way. In that part of the set-stock that comes over thevent is fitted a steel set or bolt or punch, c, the lower end of which fits close in the socket b of the ventpiece, as shown, and the other end of which passes up through the set-stock and is secured to it by a screwed collar, e. 1lhe setis made with a shoulder that bears against the under side of the set-stock, as shown, and is iitted into it loosely, so as to have a little play to enable the set to adapt itself to the socket b and the primer when it is fastened down upon them. rlhis set serves the doublepurpose of a ventbutton E,which is a disk of steel having a segment cut off from one side, as shown, and rotating upon a steel bolt, F, as a center-,which rlhis button rests.

secures it rmly to the gun. upon a lock-piece, G, which is either fastened upon the gun, as shown, or made in one piece with it, if preferred. Upon its under side itis made for apart of its circumference in the form of a helical wedge or incline, like a portion of square screw-thread, as shown at g. When the button is turned by the handle f, the inclined surface g passes over the lip h of the set-stock, (which is also beveled transversely to correspond to it,) and forces the set c down upon the .priming-cap J, and holds it firmly against the force of the discharge of the gun.

I is the hammer by which the blow is given to the set c to ignite the primer. It is jointed at i to the stud K, which is screwedinto or otherwise attached to the gun, and is worked by a lanyard, L, in the same manner as the cannon-lock in common use.

J is the primer, which is also shown separately in Fig. 5. It is made of two disks of copper, the upper one of which, j, is made thin, and has its edge turned down outside of the lower one, Ic, -itting closely to it. Between these disks the fulminate m is placed. In the center of the disk k is asinall hole, into which the quill or paper case l is fixed for holding the primi11g-powder` in the usual way, which is inserted into the vent. The outside of the disk j is, madeof a diameter to t the recess b of the vent-piece, as shown in Fig. 1, where the parts are shown in position, and when the gun is fired (by striking the top of the set c with the hammer I or otherwise) the explosion of the fulminate on, expands the flange of the disk j against the sides of the recess b and cilectually closes the joint to the escape of the gas. After firing the gun the handle f of the ,button E is turned to the position shown in Fig. 1, releasing the set-stock, which is then thrown back' out of the way, and the disks j and k of the exploded primer are removed by the priming-wire or other instrument ior the purpose carried by the gunner, by thrusting it through the center of the upper disk and through the hole of the lower means they may he removed with facility.

I. m awar'c'that heretofore mechanism has been devised for closing the vent of the gun before or at the time of priming it; but in all instances that have come to my knowledge the vent in the lirst place was so modified that it could not be used in the ordinary way, and in the second place that the joint of the inclosure was made tight by the accurate litting of valves or pistons in the vent which the corrosive action and residuum of the powder would soon render inoperative; but

by my invention the vent, if necessary, may

be used in the usual way, and the copper casing of the primer forms an expanding packing that ts itself to the form of the cavity that incloses the primer and eiiectually closes the joint, although their surfaces may be considerably corroded.

The ability to use the vent with ordinary priming I regard as of great importance in connection with my apparatus for closing it.

Having thus described my invention, what I claim is- The employment, in combination with the vent of a gun, of a recess or receptacle upon the exterior thereof for containing a primer, and a vent-stopper for closing the same, and a primer with an expanding case which serves as a packing to close the joint and prevent the escape of the gas, substantially as described.

DANL. TREADWELL.

Witnesses:

WM. C. HIBBARD, JOHN PIcKERrNe. 

